1. Field of the Invention
The invention relates to an endotracheal tube designed for accurate placement in the trachea in order to administrate oxygen or anesthetic gases, and to permit thorough cleansing of the lungs during the administration of endotracheal anesthesia or during its use with life supporting systems. It includes a distal inflatable cuff to effect an air seal in order to prevent the loss of oxygen during ventilation. It is mated with a removable introducer to facilitate atraumatic passage through the larynx. In another embodiment of the invention, a curved suction catheter is provided for insertion into the endotracheal tube and a means is provided for directing this catheter into either lung of the patient.
2. Description of the Prior Art
A number of endotracheal tubes are known. For an example the Lanz Controlled Pressure Cuff Endotracheal Tube consists of a plastic canulla, a permanently bonded, high-volume, low-pressure cuff, an inflation line, and a pressure-regulating valve. Once the cuff is inflated, the pressure-regulating valve will maintain a pressure range of 25 mm./Hg on the tracheal wall during expiration. The proximate end of the tube incorporates a 15 mm. adapter, which fits standard connectors on ventilators or anesthesia equipment. There are further known the argyle TARTAN.TM. I and TARTAN.TM. II endotracheal tubes. The TARTAN.TM. I tracheal tube is a high volume, low pressure cuffed endotracheal tube, which is optionally provided with a positive locking device. The TARTAN.TM. II tracheal tube is a low pressure cuffed endotracheal tube designed to seal the trachea with low endotracheal pressure, in most situations less than 25 mm. of Hg. There is further known the American.TM. tracheal tube with a radiopaque line and a single lumen. During anesthesia aspiration of foreign material from the lungs, utilizing suction catheters can be performed through the conventional endotracheal tubes. All of the aforesaid endotracheal tubes suffer from the disadvantage that their bevelled tip, once inside the trachea, becomes useless and actually poses a hazard, because it directs the endotracheal tube to one or the other of the main bronchi, and really facilitates entry into said bronchi, should the endotracheal tube migrate distally. Also, since most endotracheal tubes of the prior art are curved, the guiding tendency of the bevelled tip is enhanced by the curves of these prior art endotracheal tubes, which help to direct the tube towards one side or the other of the carina tracheae with distal motion. This is clearly an undesired effect, as only one lung may receive the benefit of ventilation and suctioning, and the contralateral lung none, causing it to obstruct and collapse.
There is also known an Argyle Touch-Trol.TM. Suction Catheter kit which is a transparent tube, the end of which is formed with two lateral lumens, and which has a proximate end which permits a limited amount of suction control. There is also known the Regu-Vac suction catheter made by Bard-Parker, Division of Becton, Dickinson & Co.
Straight suction catheters of the prior art have many disadvantages. One disadvantage is that only two or three distal openings are provided. These generally are not sufficient to remove most of the thick and copious tracheobronchial secretions in the short period of time that is needed to perform this function. Additionally, all of the distal openings or lumina can become easily plugged, so that the suction catheter will be rendered ineffective. In some instances, all but one of these distal openings can become occluded, so that the entire suction force is transmitted to one opening at the distal end of the suction tube. In such a situation, the resultant strong suction force will injure the bronchial mucosa, even if the suction is interrupted intermittently by the finger-tip control. Additionally, because of its straight direction, the catheter is usually aimed directly towards the main carina once it leaves the distal end of the endotracheal tube. The closer that the tip of the endotracheal tube is to the carina, the less the flexibility of the tip of the suction catheter, and the more traumatic it becomes to the main carina when it abuts against its wall before it is eventually diverted to one or the other main bronchi. Finally, the marked curve of the endotracheal tube of the prior art helps to direct the suction catheter towards the side the endotracheal tube is pointed, which, as has already been pointed out, is an undesired effect.
During the process of frequent suctioning in an intubated patient, the suction catheter may hit against the main carina most of the times it is inserted, and may thus traumatize the mucosa markedly. The injury becomes directly proportional to the number of insertions in which the catheter impinges on the main carina. Additionally, because of such anatomical factors as the direction of the right main bronchus, the suction catheter may enter only into the right main bronchus each time it is inserted. At best, the cleansing process with the suction catheters of the prior art is a "hit or miss" operation.